The assumption is, one is being taught the trade properly. In my experience, that is rare.

This is exactly what I am talking about in my area. The small amount I have learned from the pre requite course and from reading on here, the more I realize what a crap job is being done around here.

Just a little story from last year. I had a family call and said they thought they had a disease on the grass in the back lawn and that I had been recommended by a friend. I told them it was probably just dry [get a lot of those calls] but they said they a irrigation system installed at the end of 2011. I go by and sure enough it is just dry. I check out the system and the three zones in the back are working and all areas are being hit pretty good. I then start looking at the rotors and all of the are 2.5gpm. They had QT, HT and fulls all on the same zone and all 2.5. I told the homeowners since the system was pretty new that they needed to get the installer to change these out so they would be matched PR. Well, they called the guy and he said that was BS and he had been doing irrigation for X number of years and that I should stick to what I know. Since they did not fully believe me I had them water with their hose and old sprinkler along with a rain gauge, and wouldn't you know it, those areas started greening up and doing good.

I'm sorry, but I do not want this long time irrigator training me or anyone else.